Investec Champions Cup final: Northampton Saints v Bordeaux-Begles
Venue: Principality Stadium, Cardiff Date: Saturday 24 May Kick-off 14:45 BST
Coverage: Live TV coverage on Welsh language channel S4C on iPlayer, live radio coverage on BBC Radio 5 Live and BBC Radio Northampton, with live text commentary on the BBC Sport website
Joel Bielle-Biarrey remembers the conversation. And his own disbelief.
“The physical trainer at Grenoble rang me and and said, ‘Joel, your son is running really fast’.
“I asked ‘how fast?’ and he said, ‘faster than anyone else in the club. Including the professionals.’
“I just said ‘Really?'”
At the time, Grenoble had just been relegated from the French top flight. And Louis, Joel’s son, was only 17.
Even to a father’s eye, there had been little sign of that speed.
A season before, Louis had been a fly-half. A good one, but not earmarked for greatness.
“Until 16, he wasn’t on anyone’s radar,” says Joel. “He was playing for Grenoble, but he wasn’t part of their academy or the national age groups.
“He wasn’t fast at all, one of the skinniest in the team, certainly not able to dominate physically.
“But at 17 he suddenly grew up.
“He already had the step, the vision, the kicking game, the skills, but the speed and power came late.
“When Louis had those two ingredients, and put everything together… pheh, he was off.”
And he hasn’t stopped since.